Kettle One | CO2 Rocket Engine
Have you ever wanted a rocket pack to soar amongst the sky? Now you can … on Mars… Gravity is less, atmospheric density is less, and the vistas are breathtaking. So come to Mars...
Buck Rogers aside, Mars is an interesting environment for out-of-this-world mobility options for an explorer. This challenge asks for the definition of a conceptual mobility solution to allow an astronaut to easily and rapidly explore Mars including overcoming obstacles such as cliffs, ravines and other difficult terrain. The solution should be person-portable and any means or source of propulsion be locally produced.
This challenge can be answered by:
- producing an app to simulate your adventures in building your jet pack and flying around Mars;
- produce an app that provides the local gravity, atmospheric conditions (density, weather, anything-else-of-interest) to help decide what is needed for your jet pack design;
- perform a feasibility/conceptual study of an actual jet pack design that could use potential Mars fuel sources; or Design and Demonstrate a model scale jet pack using hardware.
On Mars, oxygen is not a viable component for use in combustible
fuels; it is expensive to transport and is not readily available for harvest.
We've solved this problem by designing an electric CO2 rocket engine. Introducing Kettle One.
Our engine heats a fluid with high thermal conductivity (such as
On Mars, oxygen is not a viable component for use in combustible
fuels; it is expensive to transport and is not readily available for harvest.
We've solved this problem by designing an electric CO2 rocket engine. Introducing Kettle One.
Our engine heats a fluid with high thermal conductivity (such as
We ran multiple simulations on our design :
We found that, with only 200kPa (two earth atmospheres) of pressure in the tank, we easily matched the velocity required to provide 10m/s^2 acceleration, or roughly ~2.7 martian G's. This is possible as the pressure of the atmosphere on Mars is incredibly low (~600Pa). Using the thrust equation we found the exit velocity of CO2 exhaust required for 10m/s/s acceleration of a payload, with 160kg of mass through a 5cm radius nozzle, is 327.44 m/s (the simulation above shows sufficient exit velocities in excess of 360m/s), which helped us determine the required tank pressure.
We designed a heated turbine in the bottom of the tank. In order to ensure a complete solution for the weekend however, we settled instead on a primitive coil mechanism for heating the toluene fluid, though this turbine could be easily be driven by the exhaust.
As Toluene melts at -95*C, and boils at 111*. The required temperatures for successful operation and sublimation of the Kettle One engine on Mars are remarkably low (when compared to combustion powered fuel sources), we found that the entire assembly (with exception of heating implements) could be easily 3D printed on Mars. This makes our solution not only cheap to power, but also cheap to transport and construct. The same method of driving the Kettle could also be used to drive generators, potentially solving a large resource problem for life on Mars in a simple and elegant way.
See the website for images of construction.
- PVC piping
- 2 electric 2200W kettles (the first one broke... so we bought another)
- Dry ice
- Lots of tools and coffee
- Simulation software
